Rotary piston machine with rotary pistons one arranged
within and eccentrically with regard to the other



Feb. 28, 1967 K. OPPERMANN 3,306,531 ROTARY PISTON MACHINE WITH ROTARY PISTONS ONE ARRANGED WITHIN AND ECCENTRICALLY WITH REGARD TO THE OTHER Filed Sept. '7, 1965 2 Sheets-Sheet 1 F ig. I

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United States Patent 3 306,531 ROTARY PISTON MACHINE WITH ROTARY PlS- TONS ONE ARRANGED WITHIN AND ECCEN- TRICALLY WITH REGARD TO THE OTHER Klaus Oppermann, Berlin, Germany, assignor to Borsig Aktiengesellschaft, Berlin-Tegel, Germany, and Wankel G.m.b.H., Lindau (Bodensee), Germany Filed Sept. 7, 1965, Ser. No. 485,495 Claims priority, application Germany, Sept. 14, 1964, B 78,526 Claims. (Cl. 230-441) The present invention relates to a specific embodiment of a rotary piston machine which is equipped with rotary pistons having teeth and being arranged eccentrically one within the other. With such a machine the working medium is respectively introduced and exhausted through insert members which are fixedly connected to the housing and serve as bearing means for the inner rotary piston. With a machine of this type, whether designed as onestage or two-stage machine, the outer rotary piston or pistons is or are centered in a barrel jacket journalled at both ends in the housing, while said outer rotary piston or pistons is or are axially braced and positively connected to said barrel jacket.

It is an object of the present invention to provide a rotary piston machine of the above-mentioned type, which will permit a direct coupling between the rotary piston machine and a machine to be driven thereby or driving the same.

It is another object of this invention to provide a rotary piston machine which is relatively simple in construction and reliable in operation.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIGURE 1 is a longitudinal section through a two-stage rotary piston compressor, said section being taken along the line II of FIGURE 2;

FIGURE 2 is a cross-section taken along the line 11-11 of FIGURE 1;

FIGURE 3 is a longitudinal section through a onestage machine according to the invention.

A rotary piston machine of the above-mentioned type is, according to the present invention, characterized in that the drive of the barrel jacket or the output drive is effected through the input shaft or output shaft, respectively, of the inner rotary piston or pistons as well as through the intervention of a drive disc which, on one hand is coupled to one or more inner rotary piston or pistons through one or more gear pairs, and on the other hand is positively connected to the barrel jacket. The drive disc is with a two-stage machine arranged between the rotary piston bodies of the two stages, while said disc is clamped in the jacket between the two outer rotary pistons. With a one-stage design of the rotary piston machine according to the invention, said drive disc serves for directly axially bracing the outer rotary piston in the barrel jacket while simultaneously carrying the bearing stud for a bearing of the barrel jacket.

Referring now to the drawing in detail and FIGS. 1 and 2 thereof in particular, the rotary piston machine illustrated in FIGS. 1 and 2 comprises a two-stage rotary piston compressor in which the outer rotary piston 1a of the second stage and the outer rotary piston 1b of the first stage and also a drive disc 2 interposed between the outer rotary pistons 1a and 1b are centered in a barrel jacket 3 common thereto while they are axially braced with regard to each other by means of a cover 25 and positively connected to barrel jacket 3. Barrel jacket 3 is by means of bearings 4 and 5 journalled in a housing 6, bearing 5 being designed as axial guide bearing. The

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speed ratio of the inner rotary piston to the outer rotary piston of each stage is assumed to be 2:3.

The outer rotary pistons 1a and 1b extend around the three-teeth-equipped eccentrically arranged inner rotary pistons 7a and 7b which, through the intervention of drive disc 2 fixedly connected to outer rotary pistons 1a, 1b, and gear pairs 8a, 8b, are coupled to barrel jacket 3 in the same direction of rotation. Within the mantle or skirt of the inner rotary pistons 7a and 7b there are provided cutouts 9a and 9b through which the working medium passes into and out of chambers 10, 11, 12 of the second stage (FIG. 2) and the corresponding chambers of the first stage. Within the inner rotary pistons 7a and 7b there are arranged insert members 13a and 13b which are fixedly connected to housing 6 and housing cover 14 respectively. The working medium is introduced and discharged through the curved passages 15a, 15b and 16a, 16b of the insert members 13a, 13b, respectively.

Drive shaft 17a of the inner rotary piston 7a is by means of a main bearing 18a journalled in insert member 1311 and by means of a bearing 19a designed as axial guide bearing is journalled in the end portion of housing 6. Output shaft 17b of the inner rotary piston 7b is by means of its main bearing 18b journalled in the insert member 13b and by means of bearing 19b designed as axial guide bearing is journalled in housing cover 14. Main bearings 18a, 18b are arranged approximately in the center of the inner rotary pistons 7a, 7b. The curved passages 15a, 16a and 15a, 16b as well as the main bearings 18a, 1812 are in insert members 13a, 13b separated from each other in a manner known per se by a hollow chamber 20a, 20b, respectively, which is passed through by a liquid or gaseous cooling medium. Leakage gases and oil leave housing 6 through an opening 21.

Assuming that the arrangement according to FIGS. 1 and 2 is to be operated as a two-stage compressor, shaft 17a is first coupled to a prime mover and rotated thereby. As a result thereof, the inner rotary piston 7a rotates and in turn causes the drive disc 2 to rotate through the intervention of the pair of gears 8a and also causes the inner rotary piston 7b of the first stage to rotate through the intervention of the pair of gears 8b. Drive disc 2 transmits its rotary movement to outer pistons 1a and 1b and to barrel jacket 3. When the air to be compressed is introduced through passage 15b into the first stage and leaves the first stage through outlet passage 16b, the air is conveyed to inlet passage 15a of the second stage.

FIG. 3 illustrates a one-stage rotary piston machine in which a drive disc 22 serves for the direct axial bracing of the outer rotary piston 1a in barrel jacket 23 and simultaneously carries the bearing stud 22a within a bearing 5 designed as axial guide bearing. The drive of barrel jacket 23 is efiected through drive shaft 17a of the inner rotary piston 7a, and furthermore through the intervention of drive disc 22 which, by means of gear pair 8a is coupled to the inner rotary piston 7a and is positively connected to barrel jacket 23. Leakage gases and oil leave housing 6 through an opening 24.

The illustrated machine may also, in a reverse manner, be operated as prime mover.

Furthermore, it is possible to design the teeth of the rotary pistons not only at the speed ratio of 2:3 but also at any other speed ratio n:(n+l) or (n+l):n, with n representing any figure 1, 2, 3, etc. The gear ratio of each stage may be different.

With a two-stage design of the machine mentioned above, when operating the machine as prime mover, the output drive may be effected over either shaft end.

It is, of course, to be understood, that the present invention is, by no means, limited to the particular embodiments shown in the drawings, but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. A rotary piston machine having a housing and barrel jacket means rotatably journalled in said housing, which includes: shaft means rotatably journalled in said housing, inner rotary piston means connected to said shaft means for rotation therewith, outer rotary piston means connected to said barrel jacket means for rotation therewith and eccentrically arranged with regard to and surrounding said inner piston means, said inner rotary piston means together with said outer rotary piston means and said barrel jacket means confining working chambers, said housing means being provided with passage means communicating with said chamber means for conveying a gaseous medium into and out of said chamber means, and means drivingly connecting said inner piston means with said outer piston means and said barrel jacket means.

2. A rotary piston machine according to claim 1, which includes bearing means rotatably supporting said shaft means and arranged substantially within the central portion of said inner piston means.

3. A rotary piston machine having a housing and barrel jacket means rotatably journalled in said housing which includes: shaft means rotatably journalled in said housing, inner rotary piston means connected to said shaft means for rotation therewith, outer rotary piston means connected to said barrel jacket means for rotation therewith and eccentrically arranged with regard to and surrounding said inner piston means, said inner rotary piston means together with said outer rotary piston means and said barrel jacket means confining working chambers, said housing means being provided with passage means communicating with said chamber means for conveying a gaseous medium into and out of said chamber means, rotatable disc means drivingly connected to said barrel jacket means and said outer piston means for rotating the same, and gear means respectively connected to said inner piston means and said rotatable disc means to establish driving connection therebetween.

4. A rotary piston machine having a housing and a rotatable barrel jacket, which includes: a shaft rotatably journalled in said housing, an inner rotary piston connected to said shaft for rotation therewith, an outer rotary piston connected to said barrel jacket for rotation therewith and eccentrically arranged with regard to and surrounding said inner piston and confining therewith and with said barrel jacket a plurality of working chambers, said housing being provided with passage means cornmunicating with said chambers for conveying a gaseous medium into and out of said chambers, intermeshing gears respectively connected to said inner piston and said barrel jacket, said barrel jacket having cylindrical extensions at axially opposite ends, and bearing means arranged in said housing and rotatably supporting said cylindrical extensions of said barrel jacket.

5. A rotary piston machine having a housing and barrel jacket means rotatably arranged within said housing, which includes: a first shaft rotatably journalled in one portion of said housing and protruding from one end portion thereof, a second shaft rotatably journalled in another portion of said housing and protruding from the other end portion thereof, a first inner rotary piston connected to said first shaft for rotation therewith, a second inner rotary piston connected to said second shaft for rotation therewith, a first outer rotary piston connected to said barrel jacket means for rotation therewith and eccentrically arranged with regard to and surrounding said first inner piston, a second outer rotary piston connected to said barrel jacket for rotation therewith and eccentrically arranged with regard to and surrounding said second inner piston, each of said inner rotary pistons together with the respective outer rotary piston pertaining thereto and with said barrel jacket confining Working chambers, said housing means being provided with passage means communicating with said chambers respectively pertaining to the respective adjacent inner and outer pistons for conveying a gaseous medium into and out of said chambers, rotatable drive disc means interposed between said inner pistons and in driving engagement with said outer pistons and said barrel jacket, and gear means drivingly interconnecting each of said shafts with said drive disc.

References Cited by the Examiner UNITED STATES PATENTS 2,762,195 9/1956 Nubling 103l26 2,785,637 3/1957 Nubling l03126 2,947,290 8/ 1960 Froede 12312 2,988,065 6/1961 Wankel et al 103126 3,034,484 5/1962 Stefancin 123--12 3,083,894 4/1963 Luck 230-141 3,126,755 3/1964 Luck 103126 3,232,523 22/1966 Luck 230-141 FOREIGN PATENTS 1,077,916 3/ 1960 Germany. 1,086,244 8/ 1960 Germany.

DONLEY I. STOCKING, Primary Examiner.

W. I. GOODLIN, Assistant Examiner. 

1. A ROTARY PISTON MACHINE HAVING A HOUSING AND BARREL JACKET MEANS ROTATABLY JOURNALLED IN SAID HOUSING, WHICH INCLUDES: SHAFT MEANS ROTATABLY JOURNALLED IN SAID HOUSING, INNER ROTARY PISTON MEANS CONNECTED TO SAID SHAFT MEANS FOR ROTATION THEREWITH, OUTER ROTARY PISTON MEANS CONNECTED TO SAID BARREL JACKET MEANS FOR ROTATION THEREWITH AND ECCENTRICALLY ARRANGED WITH REGARD TO AND SURROUNDING SAID INNER PISTON MEANS, SAID INNER ROTARY PISTON MEANS TOGETHER WITH SAID OUTER ROTARY PISTON MEANS AND SAID BARREL JACKET MEANS CONFINING WORKING CHAMBERS, SAID HOUSING MEANS BEING PROVIDED WITH PASSAGE MEANS COMMUNICATING WITH SAID CHAMBER MEANS FOR CONVEYING A GASEOUS MEDIUM INTO AND OUT OF SAID CHAMBER MEANS, AND MEANS DRIVINGLY CONNECTING SAID INNER PISTON MEANS WITH SAID OUTER PISTON MEANS AND SAID BARREL JACKET MEANS. 